Uncommon blood type ‘linked with increased risk of memory loss’

People with the rare blood type AB are more likely than others to develop memory problems in later life, according to a new study.

Published in the journal Neurology, the research showed that people with AB blood are 82 percent more likely to develop thinking and memory problems associated with dementia than those with other blood types.

More than 30,000 people were followed for an average of 3.4 years for this study, with 495 individuals developing cognitive impairment. Of these, six percent had the AB blood type, which is higher than the four percent of the overall population that have this type of blood.

Additionally, people in this study with higher levels of factor VIII – a protein that helps blood to clot – were 24 percent more likely to develop thinking and memory problems.

Study author Dr Mary Cushman, of the University of Vermont College of Medicine in Burlington, said: "Blood type is also related to other vascular conditions like stroke, so the findings highlight the connections between vascular issues and brain health. More research is needed to confirm these results."

There are four types of blood – A, B, O and AB. It is important that patients receiving a transfusion are given the correct type, or they could face a severe reaction.